Set up &amp; configure email server

Manage and configure SMTP server for small commercial broadcast email sender. I'm using Atom Park Email Sender but would consider switching to something else preferably server based like Dada Mail, perhaps. I have a VPS hosted by Gate and would consider switching that as well. First step would be to get things up and running. It used to work; it doesn't anymore. I don't understand why. Second step would be to optimize. Right now I'm only looking for bids for step one. You'll need knowledge/experience to evaluate the problems and fix it (them). Once running then we can consider how it could be done better. It is impossible to estimate time required, so I'm looking for hourly quotes. Once you evaluate, we can estimate the amount of work required to reach a solution. I need to start ASAP.